Princess Leonor looked completely at ease as she completed military training exercises in the snowy Pyrenees mountains with cadets from the Zaragoza Military Academy.

The 18-year-old royal, and first in line to the throne, was pictured braving the freezing cold temperatures in Astún, just days after the winter opening of the resort, prior to her hitting the slopes.

Dressed in a camouflage zip-up jacket the princess was at the- ski resort to complete a training exercise.

Said to be an accomplished skier, she was also seen carrying a large camouflage backpack and wearing brown suede walking boots as she prepared to receive lessons with her group.

The future Queen appeared in very good spirits and was quite happy as she posed for photographs with the colleagues.

According to heraldo.es, she is staying in a cabin with as many as twelve other students and was given her basic military equipment before the first training session.

During her three years at the academy, Leonor will be entitled to a salary of €417-a-month. However, the palace has said she will not claim the salary.

Rather like a boarding school, the military academy follows a strict timetable during the week. but Leonor will be free to return home at the weekends if she’s not involved with manoeuvres.

After training at the General Military Academy in Zaragoza, which is Spain’s equivalent of RMA Sandhurst, she will go to naval school, and will then complete her three years with a 12-month flying course at the General Air Academy in San Javier.

Princess Leonor’s latest appearance comes at a particularly turbulent time for the Spanish Royal Family – after Queen Letizia’s ex-brother-in-law, Jaime Del Burgo, sensationally claims the pair were romantically involved, even after she married King Felipe.

The 53-year-old, who is currently based in the UK, recently contributed to a tell-all book about Queen Letizia, “Letizia & I,” by journalist Jaime Peñafiel, in which he claimed that he had a relationship with the 51-year-old royal before he married her sister, Telma Ortiz, 50.

In the book, Del Burgo also claimed that the two were still romantically involved after Letizia tied the knot with King Felipe, 55, in 2004.